function getParameter(paramName) {
	var searchString = window.location.search.substring(1),
	  i, val, params = searchString.split("&");

	for (i=0;i<params.length;i++) {
	val = params[i].split("=");
	if (val[0] == paramName) {
	  return unescape(val[1]);
	}
	}
	return null;
}